Groupon is officially on the public market.

Shares of the Chicago-based daily-deals site began trading at approximately $28 a share on Friday at approximately 10:45 a.m. Shares have ranged from just under $26 to just over $31 in the first 45 minutes of trading. Thirty-five million shares were offered to the public.

The initial pricing of the stock was at $20 a share, thus allowing the company to raise $700 million. The company's S-1 filing with the Securities and Exchange Commission said the company planned to sell 30 million shares at a price between $16 and $18 a share.  

The company has a market value of approximately $12.7 billion, since much of the ownership is not available to the public. This is the highest valuation of any technology company to go public since 2004, when Google had a market cap of over $23 billion.

Groupon's valuation is higher than the $10.1 billion to $11.4 billion the company sought a few weeks ago, however the number is well short of the $25 billion valuation that was discussed earlier this year. Yet some analysts believe the company is way overvalued. Recently, research firm Morningstar valued the company at approximately $5 billion.

Between 2009 and 2010, revenue for Groupon increased from $30 million to $700 million, with analysts expecting the company to report about $2 billion in revenue in the upcoming year. However, Groupon posted a net loss of $10.6 million in the most recent quarter, which CEO Andrew Mason attributed to high marketing costs. In preparation for the IPO, Mason said the company planned to scale back marketing costs.

The IPO capped off a long period of speculation about the company. Groupon has been planning on going public for months, but pulled back due to instability in the stock market and concerns over accounting measures used in previous earnings reports. Over the last several weeks, Mason and other executives traveled across the country to pitch the stock to investors.

Today, Groupon opened for public trading on NASDAQ under the ticker symbol GRPN, Mason wrote in a blog-post.  Jason Child (CFO), Jeff Holden (SVP Product), and I had a great time on the road over the last two weeks answering the questions of prospective investors and sharing the Groupon story. We are excited to welcome many of the people we met as new shareholders.

Editor's Note: This story has been updated to provide background and reflect the latest developments.